5个竹种林下土壤营养元素含量比较     

王舒  张颖  万娟  罗睿  荣俊冬  郑郁善 《安徽农业科学》2016,(35):167-170

[目的]比较不同竹种林下土壤的营养元素含量。[方法]在福建农林大学百竹园内选取大明竹、牡竹、角竹、花巨竹和大木竹5个竹种,分别于春、夏、秋、冬4个季节对其林下土壤进行"S"型多点采样,对其氮、磷、钾含量进行测定。[结果]大明竹、牡竹、角竹、花巨竹和大木竹5个竹种林下土壤的营养元素含量皆较高,但各竹种之间的营养元素含量有显著差异,且各竹种在不同季节的营养元素含量也有明显差异。其中大明竹林下土壤的营养元素含量最高,且最为稳定,牡竹相对较差。[结论]在福建地区,大明竹对营养元素的产生及维系稳定具有良好的能力,可成为该地区城市观赏用竹及发展林下经济的优良竹种。  相似文献   

武汉主汛期小时降水变化     

康恒元  刘玉莲 《农学学报》2020,10(6):52-59

为了加强对武汉市主汛期降水气候和气候变化特征的了解,使用统计方法分析武汉市1955—2015年汛期小时降水数据。结果表明：武汉主汛期降水量443.5 mm,降水小时149 h,降水日数22.7天,降水强度19.5 mm/d;主汛期降水量05时最多28.9 mm,降水发生概率最大是04时13.1%,最小21时8.3%;主汛期内小时降水强度05时最大3.6 mm/h,16时最小1.9 mm/h;降水量、降水强度呈上升趋势,主汛期第3旬的降水强度增加趋势明显。城市防汛抗内涝应更多关注小时降水变化。  相似文献   

博斯腾湖浮游植物季节变化的研究   总被引：6，自引：0，他引：6  

赖英 《水生态学杂志》2009,30(5):103-106

针对博斯腾湖近几年面临着污染加剧、水体富营养化、渔业捕捞盲目等关键问题,采用《内陆水域渔业自然资源调查手册》有关方法,2004年通过6次有代表性采样,对博斯腾湖浮游植物数量、生物量进行了全面的分析研究。结果显示,博斯腾湖浮游植物数量最低的是4月,最高的是8月;6次采样数量为3．0×10^4～1423．2×10^4个／L,平均为393．7×10^4个／L;生物量为0,064～8,256mg/L,平均为2．969mg/L。全年以飞燕角甲藻（Ceratium hirundinella）为主要的优势种类;微囊藻（Microcystis）是全湖次优势藻,不仅在夏季出现率高,而且在寒冷且水温低的11月也多有出现;钟罩藻（Dinobryon）是喜水温较低的种类,该种类在4月为多个站的绝对优势种。  相似文献   

不同采收季节对叶用芥菜类黄酮物质含量和抗氧化活性的影响   总被引：1，自引：1，他引：1  

王萍  朱祝军 《园艺学报》2006,33(4):745-750

 以10个不同基因型叶用芥菜为试材, 研究了不同采收季节对其总酚含量、类黄酮含量和抗氧化活性的影响。结果表明春季采收的总酚含量、抗氧化活性显著高于冬季采收的。叶用芥菜含有槲皮素和山奈素两种类黄酮化合物, 春季采收的槲皮素和山奈素含量高于冬季采收的。基因型间总酚、槲皮素和山奈素的含量及抗氧化活性均存在较大的差异, 并与生长季节有极显著的互作关系, 表明生长季节对不同基因型叶用芥菜酚类物质积累和抗氧化活性有较大的影响。总酚、槲皮素和山奈素的含量分别与抗氧化活性呈极显著和显著正相关。  相似文献   

Influence of growing season and donor plant age on anther culture response of some pepper cultivars (Capsicum annuum L.)     

Nurgül Ercan  Funda A. SensoyA. Sırrı Sensoy 《Scientia Horticulturae》2006

The effects of growing season and donor plant age on anther culture in Capsicum were investigated. Pepper cultivars Kekova and Sera Demre 8 were grown under unheated greenhouse conditions in winter season and field conditions in summer season. Flower buds were collected and cultured in weekly intervals from November to May in winter and from April to December in summer. The results of this study indicated that anthers from these two pepper genotypes gave different embryogenic response to seasonal effects. Kekova cultivar gave the highest embryogenic yield in summer season while this was occurred in winter season for Sera Demre 8 cultivar. The results of the study revealed that the effect of donor plant age was also an important factor in anther culture of pepper. Since 4-month-old plants gave the highest embryo yield in both cultivars in each seasons, it is possible to say that anthers collected from old plants have sufficient embryogenic response when the optimum developmental stage is selected.  相似文献   

广西不同植被类型地表径流的研究   总被引：19，自引：1，他引：19  

黄承标  韦炳二 《林业科学》1991,27(5):490-497

1982—1989年,采用定位对比对不同植被类型的地表径流量及动态进行了观测研究。结果表明:1.不同植被类型的地表径流差异很大,草坡>针叶林>阔叶林或针阔混交林;区内各植被类型的径流系数较小,平均为0.78％,但各类型间差异很大,可达57倍强。2.地表径流的季节动态,主要受降水的季节分配规律制约;而不同植被类型的地表径流量主要受植被的树冠群体或植物群体、枯枝落叶层和土壤层的综合效能所决定。这种综合效能呈现阔叶混交林或针阔混交林大于针叶林、针叶林大于草坡地的规律。文中还建立了不同植被类型地表径流深与林外降雨量的回归模型。  相似文献   

Effect of Season on Travel Patterns and Hoof Growth of Domestic Horses     

Caitlin LewisJenifer Nadeau  MS  PhD  Thomas HoaglandMichael Darre  MS  PhD 《Journal of Equine Veterinary Science》2014

Four Morgan mares and five Morgan geldings ranging in age from 5- to 12-years-old were fitted with Global Positioning System units to determine if season has an influence on travel pattern. Body and hoof growth measurements were obtained so that the influence of season on body condition and hoof growth could be determined. Waist and heart circumference, cresty neck score, and body condition score were determined in each season. The ambient temperature and precipitation was recorded for each season. Waist circumference was the greatest (P < .05) in the spring and summer and the least in the fall and winter. Hoof growth was the greatest (P < .05) in the fall and the least in the winter. The front and rear hooves grew at similar rates in all horses. Hoof growth in geldings and mares were also similar. The average distances traveled were similar across seasons; however, the horse did numerically travel more in the spring and summer compared with the fall and winter. The range of the travel pattern was influenced by season with the horses traveling significantly less in the winter, although the average travel distances were similar. In conclusion, season in temperate zones will influence body condition, hoof growth, and pattern of travel, but the total distance traveled will be similar. Further research needs to be conducted to determine the influence of season on hoof growth and travel patterns.  相似文献   

黄河源区黑土滩人工草地牧草植物量及营养动态研究     

王彦龙  盛丽  施建军 《青海畜牧兽医杂志》2014,(3):1-3

对黄河源区黑土滩人工草地在封育和放牧两种不同管理方式下,从8月到翌年的4月进行了地上植物量及牧草营养成分动态研究,结果表明:从8月到翌年4月牧草的自然损失量为138.7g/m~2,损失率为34.3%,家畜的采食量为174.9g/m~2,草地的实际利用率为43.3%;整个冷季牧草总体营养价值呈下降趋势,封育草地粗蛋白降低了56.87%,粗脂肪降低了51.09%。该类草地在夏季属碳氮营养型(CN),冬季属碳营养型(C)。  相似文献   

季节对山羊胚胎移植中卵巢及胚胎发育的影响     

王跃卿  杨浩哲  李旭辉  程广伟  王洁琼 《安徽农业科学》2007,35(34):11106-11107

[目的]探究季节对山羊胚胎移植的影响。[方法]以波尔山羊与槐山羊、豫西白山羊的杂交后代为试验材料做胚胎移植试验,研究相同的处理方案、季节对卵巢及胚胎发育的影响。[结果]卵巢发育以繁殖季节为好,全部为良等级以上,其中好等级占66.7%,非繁殖季节没有好等级,只有良、一般等级;繁殖季节超排的卵泡基本都已排卵,达到84.2%以上,非繁殖季节超排的卵泡数量虽不少,但是排卵形成黄体的少,仅有33.3%;繁殖季节里冲出的胚胎发育到了桑椹胚至早期囊胚阶段,非繁殖季节冲出的胚胎发育到了8~16细胞期。[结论]山羊胚胎移植存在季节性因素的影响,相同的处理方案下,繁殖季节与非繁殖季节超排后卵巢发育存在差异,胚胎发育程度也存在差异。  相似文献   

高原夏季无公害西芹专家系统的开发与应用     

杨永岗 《甘肃农业科技》2005,(7):27-28

介绍了甘肃省首次研发的高原夏季无公害西芹专家系统的开发过程、主要技术及系统功能。该系统在金昌市永昌县示范,示范田西芹平均产量为12.915万kg/hm2,较对照增产19.9%,产值达51660元/hm2,较对照增值9360元/hm2。  相似文献